[Nut-upsuser] Redundant UPSes and dummy one

[Roger Price]

On Fri, 17 Jun 2022, PeReZ via Nut-upsuser wrote:

> I need to manage two UPSes but my host can set and monitor only one.

How are they connected?  What software are you using?

> So I thinked to install NUT UPS ...

NUT in itself is not a UPS.  It is a software package.

> ...  on a Raspberry to monitor both UPSes and to create a dummy ups.

I don't understand this.  If the Raspberry is monitoring the two UPSes, why do 
you need a dummy ups?

> The two UPSes are identical and both have LAN cards but I can connect them via 
> USB if desiderable.
> 
> Can I connect the Raspberry to the host via USB for dummy UPS communications?

I don't understand the topology.  A diagram would help.

> The dummy ups should do:
> - notify ON_BATTERY if both UPSes are on battery
> - if both go on LOW battery, change its status to LOW battery also
> - send a shutdown comamnd to both UPSes with a delay of 5 minutes so the host can gracefully stops all VMs and itself
> - turn off the Raspberry?

Have you seen the configuration file for a dummy UPS?  (File ups.conf) It does 
not provide such complex logic.

Roger